1. Technical Field
The present disclosure relates generally to systems, methods, and apparatus for preparing architectural panels including organic photovoltaic interlayers.
2. Background and Relevant Art
Photovoltaic (PV) modules comprise materials that generate electrical power in response to photon exposure, such as via photons from sunlight or other light sources. Conventional photovoltaic components for use in electrical generation typically comprise inorganic elements such as crystalline silicone (c-Si). Conventional inorganic photovoltaic (IPV) modules tend to have several drawbacks. For example, conventional IPV modules are typically resistant to high service or processing temperatures, but are brittle in nature and are opaque. These and other aspects of IPV modules tend to impose limitations on the use of IPV modules, including mounting configurations.
For example, the brittleness of IPVs can prevent an IPV construct from having certain shapes or structure, which can limit or hinder the aesthetics of a given structure supporting the IPV construct. This hindrance can be especially pronounced when the structure supporting the IPV construct is non-planar, angled, or curved. As a result, conventional mechanisms for creating PV panels typically include preparing solar panels in a small form, such as in the form of roof tiles, or otherwise embedding IPV cells within the construction materials themselves. Again, however, because the IPV components are typically both planar and rigid, the construction materials themselves also need to be both planar and rigid, which continues to limit the use and application of such construction materials.
Recent advances in IPV module technology, such as thin film IPV cells that are deposited as films onto a given substrate, can be produced into more flexible PV modules when embedded into flexible substrates. Examples of thin film IPV modules include photovoltaic cells made from amorphous silicone (a-Si), cadmium telluride (CdTe), copper indium gallium selenide (CIGS), and alloys thereof. Like the early generation c-Si photovoltaic module constructs, these newer photovoltaic technologies comprise inorganic elements. Unfortunately, these newer types of IPV modules are still opaque, and thus can result in undesirable shading, darkness, or lack of visibility in spaces beneath or behind the photovoltaic.
A recent generation of thin-film photovoltaic modules includes organic semiconductor materials comprising one or more forms of organic molecule nanostructures (often axially-oriented). Organic semiconductor PV materials have the benefit of tending to be less expensive than those PV constructs of inorganic components. While the preparation of organic photovoltaic (OPV) cells allows the photovoltaic cells themselves to be relatively translucent, unfortunately, OPV cells also tend to be sensitive and unstable, particularly in the presence of water and oxygen. To properly isolate OPV nodes from the elements (snow, wind, dust, etc.), manufacturers of OPV cells tend to encapsulate the cells within a flexible, thin, silicon-coated, film of oriented polyester (such as polyethylene terephthalate, or PET, and/or polybutylene terephthalate, or, PBT and the like). Manufacturers also sometimes employ halogenated fluoropolymer films such as ethylene tetrafluoroethylene (ETFE) and polyvinylidene fluoride (PVDF) due to their resistivity to UV degradation, clarity and barrier properties.
These types of encapsulating films tend to be relatively useful for most consumer applications, but, unfortunately, oxygen barrier additives/coatings and low surface energy halogenated polymers make lamination of these films difficult by conventional and scalable methods. Furthermore, OPV elements are sensitive to temperature and pressures that limit the use and restricts process-ability required to assemble these types of OPV modules for use as durable and structural exterior applications. For example, non-stabilized silicon-coated oriented PET (such as MYLAR from DUPONT) film tends to degrade when directly exposed to sunlight (e.g., in outdoor applications) for an extended period of time. (This may be since changes in the films properties and aesthetics may begin to change with more than a week of consecutive UV exposure.) Hence, degradation of the encapsulating film properties, in turn, results, ultimately, in degradation and loss of efficiency of the OPV cells.
One solution to improve the barrier and structural characteristics of the OPV cells would be to attach, such as by lamination, or encapsulate these module inside an improved barrier assembly. Unfortunately, it is not a simple matter to laminate the silicone-coated-, oriented-polyester- or fluoropolymer-film-encapsulated photovoltaics. For example, a manufacturer may desire to minimize degradation of the MYLAR film (or similarly-composed film) from UV radiation from direct sunlight by laminating the MYLAR-encapsulated components between opposing glass or resin substrates. Such lamination between opposing resin or glass substrates can improve the oxygen and water vapor barrier properties of the structure, thereby increasing the service life of the OPV cells.
For example, one method of attachment of the MYLAR/OPV system can involve the use of adhesives that cure at (or substantially near) ambient temperature via air curing, or via photo-curable cross-linking mechanisms. While room-temperature-curable adhesives tend to achieve good adhesion results to the silicon-coated oriented-polyester film, such constructs can result in significant air entrapment or contamination/debris between the oriented-polyester film/OPV module and the substrate. Such conditions increase the risk of field failure of the laminate structure.
Of course, other lamination methods that require high temperatures and pressures sufficient to fuse the substrates and OPV cells together are highly likely to ruin the underlying OPV cells, which are sensitive to high temperatures. Specifically, lamination methods that include temperatures and pressures sufficient to get the encapsulation films to a particular liquid state for fusion lamination require temperatures above that which OPV cells are able to withstand.